code: def npy_scp(tmp_path):
      p = tmp_path / "npy.scp"
      w = NpyScpWriter(tmp_path / "data", p)
      w["a"] = np.random.randn(100, 80)
      w["b"] = np.random.randn(150, 80)
      return str(p)
  
imports: import h5py
  import kaldiio
  import numpy
  import pytest
  from espnet2.fileio.npy_scp import NpyScpWriter
  from espnet2.fileio.sound_scp import SoundScpWriter
  from espnet2.train.iterable_dataset import IterableESPnetDataset
label_desc: Use image node_id 6 for calling a global function with example usage: npy_scp(tmp_path) and returns: str